Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Tricyclic antidepressant / topical antipruritic

Doxepin

Brand names: Sinequan (oral), Xepin (topical)

Doxepin is a tricyclic antidepressant; orally it is used for depression and anxiety, and a topical formulation is used for pruritus.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

It inhibits reuptake of noradrenaline and serotonin and has potent antihistaminic and antimuscarinic activity, the latter contributing to its sedative and antipruritic effects.

Prescribing in practice

  • Like other tricyclics, doxepin is cardiotoxic and dangerous in overdose, so it should be used cautiously where suicide risk or cardiac disease is present.
  • Marked sedation and antimuscarinic effects limit use in the elderly and in those with prostatic hypertrophy, glaucoma or arrhythmias.
  • Even topical application can cause significant systemic absorption and drowsiness, so application area and frequency should follow the SPC.

Monitoring

Monitor mood, suicidal ideation, sedation and cardiac and antimuscarinic effects during treatment.

Counselling the patient

  • May cause marked drowsiness; take care with driving and skilled tasks.
  • Report palpitations, fainting or severe dry mouth.
  • Do not exceed the prescribed dose and do not stop suddenly.

Evidence & guidelines

Tricyclic antidepressants are effective for depression but their overdose toxicity is well documented, informing cautious use.

Reference: SmPC Sinequan / Xepin; NICE NG222 (Depression in adults 2022); Maudsley Prescribing Guidelines 14th ed.; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways